USS Carl Vinson is heading towards North Korea but only after a string of misleading statements.
Photograph: US navy/Getty Images

A US aircraft carrier-led flotilla that the White House said last week was “steaming” towards North Korea to increase pressure on Pyongyang was actually thousands of miles away heading in the opposite direction.

The USS Carl Vinson and three other ships were on Tuesday heading towards North Korea but only after a string of misleading statements about their original course put out last week from the Trump administration.

The confusion about the flotilla’s course threatened to overshadow a visit to Japan by the US vice-president, Mike Pence, intended to demonstrate US resolve over North Korea. Speaking aboard the USS Ronald Reagan at its home port of Yokosuka on Wednesday, Pence pledged to strengthen the US presence in the Asia Pacific region.

“We will defeat any attack and beat any use of conventional or nuclear weapons with an overwhelming and effective American response,” he said.

In Washington, officials are facing questions and criticism over the location and original course of the Vinson flotilla, after it was photographed 3,500 miles away from North Korea, sailing south in the Sunda Strait at a time officials said it was sailing north.

On 11 April, the defence secretary, James Mattis, said the Vinson was “on her way up” to the peninsula. The White House spokesman, Sean Spicer, said “when you a see a carrier group steaming into an area like that [it] is clearly a huge deterrence”.

Late on Tuesday, the Pentagonsaid the aircraft carrier was finally heading north, after it had sailed south to take part in a preplanned training exercise with the Australian navy. Spokeswoman Dana White told the New York Times: “The ship is now moving north to the western Pacific. This should have been communicated more clearly at the time.”

The Carl Vinson and its strike force will not reach the seas off the Korean peninsula until next month.

On Wednesday, Spicer denied that the Trump administration misled or failed to correct news reports that the Vinson flotilla was en route to North Korea when, in fact, it was traveling in the opposite direction.

“The statement that was put out was that the Carl Vinson group was headed to the Korean peninsula. It is headed to the Korean peninsula,” Spicer said.

Pressed by reporters as to why White House officials did not attempt to clarify the conflicting information about the Vinson’s whereabouts, Spicer said neither the administration nor the military provided a timetable for the forces’ deployment to the Sea of Japan.

“I think we were asked very clearly about the use of a carrier group in terms of deterrence and foreign presence and what that meant. That’s what we discussed,” Spicer told reporters.

Speaking from Saudi Arabia on Wednesday, Mattis also refused to say that he had wrongly contributed to the narrative that an American flotilla was racing toward the Korean peninsula.

“We’re doing exactly what we said we were going to do,” Mattis said. “She will be on her way, and I’ll determine when she gets there and where she actually operates, but the Vinson is going to be part of our ensuring that we stand by our allies in the north-west Pacific.”

Joel Wit, a co-founder of the 38 North programme of the US-Korea Institute at Johns Hopkins University, said the confusion was “very perplexing” and fed into North Korea’s narrative that America is all bluster and does not follow through on threats.

“If you are going to threaten the North Koreans, you better make sure your threat is credible,” Wit said. “If you threaten them and your threat is not credible, it’s only going to undermine whatever your policy toward them is.”

A Chinese embassy official in Washington said on Wednesday: “We believe we should take important and necessary measures to show to the North Koreans that there are serious consequences for another nuclear test or another missile launch, and that’s no doubt about that.”

Adam Mount, a senior fellow at the Centre for American Progress, said that while such pledges of increased pressure on North Korea are quite common from Beijing, they are becoming more credible.

“I think the Chinese are in two minds. There are some who see North Korea as a buffer against US power, but others who see North Korea as a long-term threat to regional stability,” Mount said. “There is a transition in China now towards seeing DPRK as a threat to stability, but there will continue to be frequent backsliding and mixed messages because Chinese activity will reflect the fact there are different points of view in Beijing.”